Improvement in furnaces for steam-boilers



J. L. HEALD.

- FURNACES FOR STEAM BOILERS.

No.179,191. Patented June-27, 1876.

JOHN L. HEALD, OF VALLEJO, CALIFORNIA.

,. IMPROVEMENT IN FURNACES FOR STEAM-BOILERS.

Specification forming part of Letters Patent No. 179, 191, dated June27, 1876; application filed April 11, 1876.

To all whom it may concern Be it known that I, JOHN L. HEALD, ofVallejo, Solano county, State of California, have invented Improvementsin Boilers; and I do hereby declare the following description andaccompanying drawings are sufficient to enable any person skilled in theart or science to which it most nearly appertains to make and use mysaid invention or improvement without further invention or experiment.

My invention relates to certain improvements in boilers which areemployed to supply steam to drive engines, and it is more especiallyapplicable to that class known as field or portable engines, in which itis desirable to use wood, straw, brush, or other light fuel.

It consists of a novel attachment for the chimney or stack of theboiler, whereby I am enabled to greatly increase the draft and regulateit, so as to make steam more quickly and retain it more effectually,whatever may be the condition of'the wind or atmosphere.

My invention further consists in a novel construction of a furnace-doorturning upon a horizontal axis,,which is made adjustable, so as toregulate the size of the door-opening to receive different classes offuel, while at the same time no undesirable draft through the fire willbe permitted by this change of dooropening.

Referring to the accompanying drawings for a more complete explanationof my invention, Figure 1 is a longitudinal section. Fig. 2 is aperspective view of top of chimney and deflector. Figs. 3, 4; aretransverse sections, showing rear and front views, respectively. Fig. 4is a view of the door with its double hinges.

A is my boiler, which may be made in any suitable form; but to explaincertain parts of my invention I have shown it as made in the form wellknown as a Cornish boiler, having one large flue, B, passing through thelower part, with a grate, 0, near one end to receive the fuel, and smallreturn flues or tubes 0, that bring the heat back to the chimney D,which is situated at the furnace end of the boiler. Thecombustion-chamber F at the rear end, and the smoke-box G at the front,are in no way different from the con- .and regular combustion, as iswell known.

struction shown in the old English forms of this boiler, in which thelarge tube B passes through the flue-sheet to the front end of thesmoke-box, while the small tubes are secured at each end on theflue-sheets.

\/Vhenever the wind is blowing it is difficult in any field-engine toget a good draft in first starting a tire, because the air blowingacross the top of the chimney will cause eddies and downward currents,which prevent a rapid In order to remedy this troubleIfix to the upperpart of this chimney D a plate, H, which is .so mounted that it may beadjusted to stand in such a position as to deflect the current of airand cause an upward draft through the chimney. This is done in thepresent case by means of connecting links I I, which are pivoted to eachside of the plate, and also' to the top of the chimney, so that by meansof proper attachments the angle of the plate and its relative positionto the chimney-opening may be changed at will.

The edges of the plate are turned up, so as to make a sort of trough,and it may be found advisable in some cases to form a complete tube,bent or placed at an angle to cause the desired upward draft, the effectof which is somewhat the same as that of an injector, as this deflectedcurrent of air causes a sort of vacuum in the chimney, which will thuscreate the necessary draft.

This device is shown as pinned in one position to the chimney, and itneeds no other adjustment for-use in the fields of California, where thewinds are trades, and constant from one direction; but in case ofvariable winds, a loose band or ring may be fitted to turn upon the topof the chimney, and the connectingrods pinned to this ring, so that thedeflector can be easily adjusted to any position. After work is finishedthis deflector may be drawn across the top of the chimney to serve as adamper, and cut 0E all draft.

In order to fit my boiler for the use of (lifferent kinds of fuel, Ihave constructed a furnace-door in such amanner that the size of theopening can be easily and instantly adjusted, so that when I wish to usewood I can make the opening large enough for that purpose; out if strawor brush is to be used it is desirable to contract the door-openin g,and this may be done in various ways.

I have made use of a door, J, so mounted as to drop into a horizontalposition when open, and this door has two sets of pintles or hinges toturn on. K K are a pair of hinges, placed at the lowest part of thedoor, so that when these are used the door'will open to expose thefullsize of the furnace-opening. L L are another pair of pintles or hinges,which support the door at points nearer the center, and when it turnsupon these a small opening is left. These two pairs of hinges aremounted upon the ends of a plate or lever, m, which is pivoted to turnin the center, and is secured to the side, as shown. v

It will be seen that when this plate is turned so that one pair ofpintles enter the sockets made for them the other will be withdrawn, andthus the change from a large to a small opening, or vice versa, will beeasily accomplished without removing the door from its hinges. When thedoor is turned upon the hinges nearest the center, the portion back ofthe hinges would be turned, so as to leave an opening for the ,entranceof air, if the door were straight, which would be undesirable, as thesmall opening is always used with light fuel, where it is necessary tokeep the air from entering except through the, grate-bars anddoor-opening itself. I therefore curve this back part of the door into asemicircle, as at 'n, so that when it turns upon the pintles L L thissemicircle will just fill the opening below the pintles, and prevent theentrance of air at that point.

In the use of straw for a fuel, a fierce draft is caused through thelarge flue, and the heat strikes the rear cap or door O so strongly asto make it red-hot and burn it out. I remedy this by placing one or moretubes, 1?, transvcrsely across the large flue near the rear end, asshown, and these serve to divide or deflect the flame, and by thisdeflection partially across the large flue at or near the end of thegrate-bars. I find that all grate-bars placed across the large flue toprevent the straw from passing to the combustion chamber soon burn out.I also find that tubes placed across the large flue at the end of thegratebarsincreases the heating capacity of the boiler very.:much, andaids the circulation of the water in the boiler.

The front head or cap Q of the smoke-chamberis always hinged, so as tobe readilyopened for the purpose of cleaning out this chamber, and theash -pan It, which I desire to use, would be in the way and strike thewheels of the engine when this door is opened, if made stationary. Itherefore make two sockets upon the lower side of this door, and twoarms, S, secured to the ash-pan, are so bent as to enter these sockets,thus making the ashpan removable at will.

The door J, when in its horizontal position,

just fills the flue, and may rest upon short flanges, thus preventingstraw from falling into the ashes in the lower part.

Having thus described my invention, what I claim, and desire to secureby Letters Patent,

1. In a straw-burning furnace, the grate 0, large flue B, return-flues ee,and chimney D, :in combination with the deflector H, adjustably hingedor attached, so as to cause an upward draft of air in the chimney bychanging the current of air as it passes across, substantial] y asandct'or the purpose described.

2. The door J, turning upon the hinges K or L, said hinges beingarranged in pairs, so

that, changing from one pair of hinges to the other, the opening of thedoor will disclose a larger or smaller space for firing, substantiallyas herein described.

3. The lever-arms m, centrally pivoted, and carrying the pintles orhinges K and L at either end, so that, by turning on their points ofsupport, one pair of pintlcs will be thrown into their sockets tosupport the door, and the other pair released, substantially as hereindescribed. turn it and prepare it to enter the return-fines.

4. The door J, with its two sets of hinges K and L, and having its loweredge formed into a semicircle, with the center L as a radius, so thatwhen the smallest fuel-opening is disclosed, the semicircle will preventthe entrance of air to the furnace below the axis of motion of the door,substantially as described.

JOHN L. HEALD. Witnesses:

GEo. H. STRONG, O. M. RICHARDS.

